Emergency department echocardiography improves outcome in penetrating cardiac injury

Bedside emergency cardiac ultrasound in children

Bedside emergency ultrasound has rapidly developed over the past several years and has now become part of the standard of care for several applications. While it has only recently been applied to critically ill pediatric patients, several of the well-established adult indications may be applied to pediatric patients. One of the most important and life-saving applications is bedside echocardiography. While bedside emergency ultrasonography does not serve to replace formal comprehensive studies, it serves as an extension of the physical examination. It is especially useful as a rapid and effective tool in the diagnosis of pericardial effusions, tamponade and in distinguishing potentially reversible causes of pulseless electrical activity from asystole. Most recently, left ventricular function and inferior vena cava measurements have proven helpful in the assessment of undifferentiated hypotension and shock in adults and children. Future research remains to be carried out in determining the efficacy of bedside ultrasonography in pediatric-specific pathology such as congenital heart disease. This article serves as a comprehensive review of the adult literature and a review of the recent applications in the pediatric emergency department. It also highlights the techniques of bedside ultrasonography with examples of normal and pathologic images.

Prehospital ultrasound by paramedics: results of field trial

OBJECTIVES

The objective was to determine if 9-1-1 paramedics trained in ultrasound (US) could adequately perform and interpret the Focused Assessment Sonography in Trauma (FAST) and the abdominal aortic (AA) exams in the prehospital care environment.

METHODS

Paramedics at two emergency medical services (EMS) agencies received a 6-hour training program in US with ongoing refresher education. Paramedics collected US in the field using a prospective convenience methodology. All US were performed in the ambulance without scene delay. US exams were reviewed in a blinded fashion by an emergency sonographer physician overreader (PO).

RESULTS

A total of 104 patients had an US performed between January 1, 2008, and January 1, 2009. Twenty AA exams were performed and all were interpreted as negative by the paramedics and the PO. Paramedics were unable to obtain adequate images in 7.7% (8/104) of the patients. Eighty-four patients had the FAST exam performed. Six exams (6/84, 7.1%) were read as positive for free intraperitoneal/pericardial fluid by both the paramedics and the PO. FAST and AA US exam interpretation by the paramedics had a 100% proportion of agreement with the PO.

CONCLUSIONS

This pilot study shows that with close supervision, paramedics can adequately obtain and interpret prehospital FAST and AA US images under protocol. These results support a growing body of literature that indicates US may be feasible and useful in the prehospital setting.

An Evidence-Based Approach for Integrating Bedside Ultrasound Into Routine Practice in the Assessment of Undifferentiated Shock

Undifferentiated hypotension remains a central diagnostic and therapeutic challenge in emergency and critical care medicine. Increasingly, bedside ultrasound conducted by intensivists and emergency medicine providers is assuming a central role in diagnosis and resuscitation of hypotension. This review discusses sample algorithms for the bedside ultrasonographic assessment of undifferentiated shock and outlines an evidence-based framework for the intensivist seeking to incorporate bedside ultrasound into daily clinical practice. The literature regarding specific applications including cardiac, thoracic, pulmonary, and vascular assessment is briefly reviewed, as is the evidence pertaining to effective implementation, training, credentialing, and ongoing quality assurance.

Ultrasound in trauma

Point-of-care ultrasound is well suited for use in the emergency setting for assessment of the trauma patient. Currently, portable ultrasound machines with high-resolution imaging capability allow trauma patients to be imaged in the pre-hospital setting, emergency departments and operating theatres. In major trauma, ultrasound is used to diagnose life-threatening conditions and to prioritise and guide appropriate interventions. Assessment of the basic haemodynamic state is a very important part of ultrasound use in trauma, but is discussed in more detail elsewhere. Focussed assessment with sonography for Trauma (FAST) rapidly assesses for haemoperitoneum and haemopericardium, and the Extended FAST examination (EFAST) explores for haemothorax, pneumothorax and intravascular filling status. In regional trauma, ultrasound can be used to detect fractures, many vascular injuries, musculoskeletal injuries, testicular injuries and can assess foetal viability in pregnant trauma patients. Ultrasound can also be used at the bedside to guide procedures in trauma, including nerve blocks and vascular access. Importantly, these examinations are being performed by the treating physician in real time, allowing for immediate changes to management of the patient. Controversy remains in determining the best training to ensure competence in this user-dependent imaging modality.

Financial impact of emergency department ultrasound

OBJECTIVES

There is limited information on the financial implications of an emergency department ultrasound (ED US) program. The authors sought to perform a fiscal analysis of an integrated ED US program.

METHODS

A retrospective review of billing data was performed for fiscal year (FY) 2007 for an urban academic ED with an ED US program. The ED had an annual census of 80,000 visits and 1,101 ED trauma activations. The ED is a core teaching site for a 4-year emergency medicine (EM) residency, has 35 faculty members, and has 24-hour availability of all radiology services including formal US. ED US is utilized as part of evaluation of all trauma activations and for ED procedures. As actual billing charges and reimbursement rates are institution-specific and proprietary information, relative value units (RVUs) and reimbursement based on the Centers for Medicare & Medicaid Services (CMS) 2007 fee schedule (adjusted for fixed diagnosis-related group [DRG] payments and bad debt) was used to determine revenue generated from ED US. To estimate potential volume, assumptions were made on improvement in documentation rate for diagnostic scans (current documentation rates based on billed volume versus diagnostic studies in diagnostic image database), with no improvements assumed for procedural ED US. Expenses consist of three components-capital costs, training costs, and ongoing operational costs-and were determined by institutional experience. Training costs were considered sunken expenses by this institution and were thus not included in the original return on investment (ROI) calculation, although for this article a second ROI calculation was done with training cost estimates included. For the purposes of analysis, certain key assumptions were made. We utilized a collection rate of 45% and hospitalization rates (used to adjust for fixed DRG payments) of 33% for all diagnostic scans, 100% for vascular access, and 10% for needle placement. An optimal documentation rate of 95% was used to estimate potential revenue.

RESULTS

In FY 2007, 486 limited echo exams of abdomen (current procedural terminology [CPT] 76705) and 480 limited echo cardiac exams were performed (CPT 93308) while there were 78 exams for US-guided vascular access (CPT 76937) and 36 US-guided needle placements when performing paracentesis, thoracentesis, or location of abscess for drainage (CPT 76492). Applying the 2007 CMS fee schedule and above assumptions, the revenue generated was 578 RVUs and $35,541 ($12,934 in professional physician fees and $22,607 in facility fees). Assuming optimal documentation rates for diagnostic ED US scans, ED US could have generated 1,487 RVUs and $94,593 ($33,953 in professional physician fees and $60,640 in facility fees). Program expenses include an initial capital expense (estimated at $120,000 for two US machines) and ongoing operational costs ($68,640 per year to cover image quality assurance review, continuing education, and program maintenance). Based on current revenue, there would be an annual operating loss, and thus an ROI cannot be calculated. However, if potential revenue is achieved, the annual operating income will be $22,846 per year with an ROI of 4.9 years to break even with initial investment.

CONCLUSIONS

Determining an ROI is a required procedure for any business plan for establishing an ED US program. Our analysis demonstrates that an ED US program that captures charges for trauma and procedural US and achieves the potential billing volume breaks even in less than 5 years, at which point it would generate a positive margin.

Transesophageal echocardiography and noncardiac surgery

The use of transesophageal echocardiography (TEE) for monitoring during cardiac and noncardiac surgery has increased exponentially over the past few decades. TEE has evolved from a diagnostic tool to a monitoring device and a procedural adjunct. The close proximity of the TEE transducer to the heart generates high-quality images of the intracardiac structures and their spatial orientation. The use of TEE in noncardiac and critical care settings is not well studied, and the evidence of the benefits of its use in these settings is lacking. Despite the widespread availability of TEE equipment in US hospitals, less than 30% of anesthesiologists are formally trained in the use of perioperative TEE. In this review, the safety and indications of TEE are reviewed and detailed analysis of the best available evidence in this regard is presented. Landmark trials evaluating the use of TEE and its therapeutic impact in noncardiac surgical setting are critically reviewed. This article details recommendations to familiarize anesthesiologists with TEE technology to exploit it to its fullest potential to achieve better patient monitoring standards and eventually improve outcome. Training of greater numbers of anesthesiologists in TEE is needed to increase awareness of the indications and contraindications. Until relatively inexpensive TEE equipment is available, the initial cost of equipment acquisition remains a significant prohibitive factor limiting its widespread use.

Bedside ultrasound in the pediatric emergency department

PURPOSE OF REVIEW

Emergency bedside ultrasound has been used by emergency and critical care physicians for over two decades. Its use has grown rapidly in emergency medicine and the range of diagnostic and procedural applications has continued to expand; only recently, however, has this tool been embraced by pediatric emergency and critical care physicians. As this technology develops and becomes more available pediatricians should understand its uses and limitations.

RECENT FINDINGS

Use of emergency bedside ultrasound for victims of trauma and for procedural applications such as central venous access are well established in adults. Recent published studies suggest that utilizing bedside ultrasound for these purposes may be beneficial in pediatric emergency medicine. Other reports portend future pediatric applications such as assessment of volume status and dehydration, fracture identification and reduction, and aiding in the performance of lumbar punctures.

SUMMARY

In a review of the literature, it is clear that emergency bedside ultrasound has a role in pediatric emergency and critical care medicine. Much more research is needed, however, to determine which sonographic assessments are of the greatest value. Collaborative efforts will likely be needed to establish definitive applications.

Bedside ultrasound in pediatric emergency medicine

Bedside emergency ultrasound has been used by emergency physicians for >20 years for a variety of conditions. In adult centers, emergency ultrasound is routinely used in the management of victims of blunt abdominal trauma, in patients with abdominal aortic aneurysm and biliary disease, and in women with first-trimester pregnancy complications. Although its use has grown dramatically in the last decade in adult emergency departments, only recently has this tool been embraced by pediatric emergency physicians. As the modality advances and becomes more available, it will be important for primary care pediatricians to understand its uses and limitations and to ensure that pediatric emergency physicians have access to the proper training, equipment, and experience. This article is meant to review the current literature relating to emergency ultrasound in pediatric emergency medicine, as well as to describe potential pediatric applications.

Current issues with emergency cardiac ultrasound probe and image conventions

As emergency physicians (EPs) and other noncardiologists incorporate bedside ultrasound (US) and bedside echocardiography (echo) into their practice, confusion has resulted from the differing imaging conventions used by cardiac and general imaging. The author discusses the origin of these differences, current cardiac imaging conventions, and controversies in emergency medicine (EM) regarding adoption of imaging conventions. Also discussed in detail are specific echo windows and experience with different approaches. While there is no perfect solution to merging the differing conventions, it is important that those performing and teaching bedside US and echo have a thorough understanding of the issues involved, and adopt a consistent approach.

Practical recommendations for prehospital and early in-hospital management of patients presenting with acute heart failure syndromes

Guideline recommendations for the prehospital and early in-hospital (first 6-12 hrs after presentation) management of acute heart failure syndromes are lacking. The American College of Cardiology/American Heart Association and European Society of Cardiology guidelines direct the management of these acute heart failure patients, but specific consensus on early management has not been published, primarily because few early management trials have been conducted. This article summarizes practical recommendations for the prehospital and early management of patients with acute heart failure syndromes; the recommendations were developed from a meeting of experts in cardiology, emergency medicine, and intensive care medicine from Europe and the United States. The recommendations are based on a unique clinical classification system considering the initial systolic blood pressure and other symptoms: 1) dyspnea and/or congestion with systolic blood pressure >140 mm Hg; 2) dyspnea and/or congestion with systolic blood pressure 100-140 mm Hg; 3) dyspnea and/or congestion with systolic blood pressure <100 mm Hg; 4) dyspnea and/or congestion with signs of acute coronary syndrome; and 5) isolated right ventricular failure. These practical recommendations are not intended to replace existing guidelines. Rather, they are meant to serve as a tool to facilitate guideline implementation where data are available and to provide suggested treatment approaches where formal guidelines and definitive evidence are lacking.

Toward an ultrasound curriculum for critical care medicine

Accurate assessment and rapid decision-making are essential to save lives and improve performance in critical care medicine. Real-time point-of-care ultrasound has become an invaluable adjunct to the clinical evaluation of critically ill and injured patients both for pre- and in-hospital situations. However, a high level of quality is necessary, guaranteed by appropriate education, experience, credentialing, quality control, continuing education, and professional development. Although educational recommendations have been proposed by a variety of nonimaging specialties, to date they are still scattered and limited examples of standards for critical and intensive care professionals. The challenge of providing adequate specialty-specific training, as encouraged by major medical societies, is made even more difficult by the diversity of critical care ultrasound utilization by various subspecialties in a variety of settings and numerous countries. In order to meet this educational challenge, a standard core curriculum is presented in this manuscript. The proposed curriculum is built on a competence, performance, and outcomes-based approach that is tailored to setting-specific training needs and prioritized according to critical problem-based pathways, rather than traditional organ-based systems. A multiple goal-oriented style fully addresses the specialty-specific approach of critical and intensive care professionals, who typically deal with disease states in complex scenarios rather than individual organ complaints. Because of the variation in the concept of what constitutes critical care worldwide, and the rate of change of information and technology, this manuscript attempts to present a learning system addressing a variety of needs for a rapidly changing world.

Impending cardiac tamponade: A case report highlighting the value of bedside echocardiography

Cardiac tamponade is a life-threatening process that must be diagnosed and treated in a timely fashion. As blood fills the pericardial sac, right ventricular filling is impeded and cardiac output is diminished, ultimately leading to cardiovascular collapse. Fortunately, emergency ultrasonography has improved the way we manage these patients today. In this report, we discuss a patient with hypotension and tachycardia who was found to have a massive loculated posterior pericardial effusion with impending cardiac tamponade. The diagnosis and appropriate treatment of this patient were rapidly ascertained with the use of bedside echocardiography. We review the literature on emergency ultrasonography, and consider the numerous instances in which emergency echocardiography can be life-saving.

Randomized controlled clinical trial of point-of-care, limited ultrasonography for trauma in the emergency department: the first sonography outcomes assessment program trial

STUDY OBJECTIVE

Annually, 38 million people are evaluated for trauma, the leading cause of death in persons younger than 45 years. The primary objective is to assess whether using a protocol inclusive of point-of-care, limited ultrasonography (PLUS), compared to usual care (control), among patients presenting to the emergency department (ED) with suspected torso trauma decreased time to operative care.

METHODS

The study was a randomized controlled clinical trial conducted during a 6-month period at 2 Level I trauma centers. The intervention was PLUS conducted by verified clinician sonographers. The primary outcome measure was time from ED arrival to transfer to operative care; secondary outcomes included computed tomography (CT) use, length of stay, complications, and charges. Regression models controlled for confounders and analyzed physician-to-physician variability. All analyses were conducted on an intention-to-treat basis. Results are presented as mean, first-quartile, median, and third-quartile, with multiplicative change and 95% confidence intervals (CIs), or percentage with odds ratio and 95% CIs.

RESULTS

Four hundred forty-four patients with suspected torso trauma were eligible; 136 patients lacked consent, and attending physicians refused enrollment of 46 patients. Two hundred sixty-two patients were enrolled: 135 PLUS patients and 127 controls. There were no important differences between groups. Time to operative care was 64% (48, 76) less for PLUS compared to control patients. PLUS patients underwent fewer CTs (odds ratio 0.16) (0.07, 0.32), spent 27% (1, 46) fewer days in hospital, and had fewer complications (odds ratio 0.16) (0.07, 0.32), and charges were 35% (19, 48) less compared to control.

CONCLUSION

A PLUS-inclusive protocol significantly decreased time to operative care in patients with suspected torso trauma, with improved resource use and lower charges.

Usefulness of hand-held ultrasound devices in out-of-hospital diagnosis performed by emergency physicians

OBJECTIVE

To evaluate the usefulness of ultrasonographic examinations as a diagnostic tool for emergency physicians in out-of-hospital settings.

METHODS

Prospective study performed in a French teaching hospital. Eight emergency physicians given ultrasound training for out-of-hospital diagnosis of pleural, peritoneal, or pericardial effusion; deep venous thrombosis; and arterial flow interruption. After clinical examination, a probability of diagnosis ("clinical score") was assigned on visual analog scale from 0 (absent lesion) to 10 (present lesion). Clinical score between 3 and 7 was considered as clinically doubtful. After ultrasound examination, a second probability ("ultrasound score") was similarly determined. Potential usefulness of ultrasound examination was evaluated by calculating the absolute difference between clinical and ultrasound scores. Patients were followed up to determine final diagnosis: present or absent lesion. "Ultrasound usefulness score" (USS) was determined attributing a positive (when ultrasonography increased diagnostic accuracy) or a negative (when ultrasonography decreased diagnostic accuracy) value to the absolute difference between clinical and ultrasound scores.

RESULTS

One hundred sixty-nine patients were included and 302 ultrasound examinations performed. Median duration of examination was 6 minutes (5-10 minutes). The suspected lesion was found in 45 cases (17%). Mean USS was +2 (0-4). Ultrasonographic examination improved diagnostic accuracy (ie, positive USS) in 181 (67%) cases, decreased it (ie, negative USS) in 22 (8%) cases, and was not contributive (ie, USS was 0) in 67 (25%) cases. When initial diagnosis was uncertain (n = 115), diagnostic performance reached +4 (3-5) and ultrasonographic examination improved diagnostic accuracy in 103 (90%) cases.

CONCLUSION

Out-of-hospital ultrasonography increased diagnostic accuracy in out-of-hospital settings.

The association between operator confidence and accuracy of ultrasonography performed by novice emergency physicians

The variable accuracy of emergency department (ED) ultrasound described in the literature has limited its utility as the sole imaging modality in critical decision making. Although ultrasound accuracy is highly dependent upon the technical abilities of the operator and conditions unique to each patient, no previous study of ED ultrasound has included estimates of operator confidence. This prospective observational study explores the association between operator confidence and the accuracy of ED ultrasound. Ultrasound was not performed in our ED until a formal training module was instituted. Patients were enrolled prospectively for the first year following the training module if they underwent one of the following ultrasound studies: abdominal examination for intraperitoneal fluid, right upper quadrant examination for gallstones, renal examination for hydronephrosis, pelvic examination for intrauterine pregnancy, abdominal examination for aorta diameter > 3 cm, or cardiac examination for pericardial fluid. In addition, formal ultrasound, computed tomography, magnetic resonance imaging, or an invasive procedure was required as a "gold standard" for each patient. Operators recorded their interpretation of the ED ultrasound and rated their confidence with the analysis before the formal imaging study or procedure. Test performance characteristics for each examination type and for all studies together were determined. The association between operator confidence and accuracy was explored using logistic regression and by determining test performance characteristics with patients stratified by confidence value. A total of 276 ED ultrasound studies were included. There were no significant differences in accuracy between ED attendings and residents. Overall accuracy, sensitivity, specificity, LR+, and LR- were 90%, 92%, 86%, 6.8, and 0.09, respectively. With confidence scores of 9 or 10 (n = 113), these values improved to 96%, 99%, 90%, 9.6, and 0.01, respectively. Logistic regression revealed an association between confidence and ED ultrasound accuracy (p < 0.001). It is concluded that a significant association exists between operator confidence and the accuracy of ED ultrasound. High confidence values are associated with clinically useful test performance characteristics.

Feasibility of FAST examination performance with ultrasound contrast

The Focused Abdominal Sonography in Trauma (FAST) examination has several limitations, among which is the inability to reliably detect solid organ injury. We sought to evaluate the feasibility of ultrasound contrast use during a FAST examination and its effect on the ability to delineate vasculature in the spleen and liver from hilum to capsule on simulated patients. This prospective observational case control study was conducted at an urban community hospital Emergency Department (ED) that is a level I trauma facility. During a FAST examination, the liver and spleen were scanned in entirety to evaluate contrast opacification of blood vessels and a latent phase highlighting the parenchyma of the liver and spleen. Each physician, hospital credentialed for the use of emergency ultrasound, scanned the liver and spleen both before and after contrast administration. Five milliliters of contrast were mixed with 16 mL of normal saline and then injected 4 mL at a time through an 18-gauge anticubital catheter. All examinations were successfully completed before contrast agent dissipation. The mean time to complete the FAST examination with interrogation of the liver and spleen was 1 min 42 s (range 1 min 22 s to 2 min 5 s). The mean time to initial visualization of contrast was 15 s (range 12 to 18 s). The latent phase of the ultrasound contrast when the liver or spleen began to shimmer, an effect that would outline hematomas not actively bleeding, occurred at a mean time of 54 s (range 45 s to 1 min 9 s). The ultrasound contrast disappeared at a mean of 2 min 52 s (range of 2 min 16 s to 3 min 33 s). In conclusion, ultrasound contrast use is feasible during the FAST examination and allows enhanced evaluation of solid organ parenchyma during evaluation for solid organ injury.

Fascial Ultrasound for Evaluation of Anterior Abdominal Stab Wound Injury

BACKGROUND

Local stab wound (SW) exploration to assess abdominal fascial integrity is a highly invasive procedure frequently performed under demanding circumstances in the Emergency Department (ED). We hypothesized ultrasound (U/S) may be useful in the detection of fascial defects resulting from anterior abdominal stab injury, eliminating the need for local wound exploration

METHODS

Thirty-five hemodynamically normal patients evaluated at a Level I trauma center for anterior abdominal stab wounds were examined by U/S (8 mHz probe) for evidence of fascial violation. All patients were subsequently evaluated by local wound exploration

RESULTS

Fascial U/S had an overall sensitivity of 59% and specificity of 100%, (PPV 100%, NPV 59%) for detection of fascial SW defects compared with local wound exploration. The sensitivity of fascial U/S for stab wound evaluation varied directly with experience of the sonographer

CONCLUSIONS

A positive fascial U/S obviates the need for invasive SW exploration; however, a negative fascial U/S does not preclude the need for local wound exploration. Resident U/S training for specific penetrating injuries may reduce the need for abdominal SW fascial exploration in the ED.

Red flag in the emergency department: fracture and primary failure of a prosthetic valve

This case report concerns a patient with fracture and primary dysfunction of a prosthetic valve. A 40-year-old man presented to the Emergency Department with a chief complaint of breakthrough pleuritic back pain and shortness of breath. Past surgical history was significant only for an aortic valve replacement and mitral valve replacement performed 16 years prior. The transthoracic echocardiography raised suspicion of prosthesis malposition. The patient was taken to the operating room by cardiothoracic surgeons for valve replacement. Operative findings revealed that a prosthetic valve leaflet in the mitral position had broken off. Primary prosthetic valve failure should not be overlooked in the differential diagnosis of patients with valve replacement and a rapidly deteriorating clinical course. Emergency echocardiography is a guide to convenient diagnosis and management. Early surgical consultation and early reparative surgery might prevent unnecessary morbidity and mortality.

Change in differential diagnosis and patient management with the use of portable ultrasound in a remote setting

OBJECTIVE

Physicians practicing in remote areas are typically limited in their choice of diagnostic tools. The goal of this study was to determine whether the use of a portable ultrasound (US) device on selected patients in a remote setting would alter physician diagnosis and management.

METHODS

This was a prospective observational study of the affects of US on physician decision making deep in the Amazon jungle. A battery-operated Sonosite 180 Plus with 2 interchangeable transducers (4-7-MHz broadband intercavitary transducer and 2-5-MHz broadband abdominal transducer) was used. The patient population consisted of local tribal people. Two of the physicians on the team performed all US examinations. Team physicians requesting US examinations filled out a survey before and after the US examination. Before the US, the referring physician filled out a survey describing the patient's initial complaint, pertinent past medical history and physical findings, and an initial (pre-US) differential diagnosis and planned treatment with expected disposition. After the results of the US were reviewed with the referring physicians, the doctors were asked to fill out the remainder of the survey, allowing comparison of pre- and post-US differential diagnosis, treatment plan, and disposition.

RESULTS

A total of 25 US studies were performed during this study (1 trauma US scan, 6 hepatobiliary studies, 5 transabdominal pelvic scans, 7 transvaginal pelvic studies, 3 renal studies, and 3 abdominal aortic scans). The monitor on the US unit experienced a rare failure shortly after being used at 17,000 ft and then 10 times at sea level, and no further US scans could be performed. US scan results dramatically altered the disposition of 7 patients, including 4 patients who avoided a potentially dangerous 2-day evacuation to more definitive medical care. Three patients were found to need rapid referral to the nearest clinic for surgical evaluation.

CONCLUSIONS

When used in a remote location, portable US provides a significant benefit that can dramatically alter disposition and treatment.

Feasibility and potential clinical utility of goal-directed transthoracic echocardiography performed by noncardiologist intensivists using a small hand-carried device (SonoHeart) in critically ill patients

OBJECTIVE

This study was designed to assess the clinical applicability of a small, handheld, portable transthoracic echocardiography device by noncardiologist intensivists.

DESIGN

Prospective, observational study. After 10 one-hour tutorials, intensivists performed a limited transthoracic echocardiography (TTE) (2-4 views, without Doppler or M-mode) examination with the 5.6-lb SonoHeart Echo System (SonoSite, Bethell, WA) on critically ill patients admitted to the surgical intensive care unit. After initial cardiac clinical assessment in 90 patients, a limited TTE was performed by an intensivist to assess left ventricular (LV) function and LV volume status. Each study was immediately reviewed and repeated by an echocardiographer to determine the technical quality of the TTE and the accuracy of the intensivist's interpretation. Data were analyzed and presented in proportions using descriptive statistics.

SETTING

Surgical intensive care unit of an academic medical center.

PARTICIPANTS

Ninety critically ill adult patients.

INTERVENTIONS

After initial cardiac clinical assessment, a limited TTE was performed by an intensivist to assess LV size and function, to rule out significant pericardial effusions, and to estimate circulatory volume.

RESULTS

Intensivists successfully performed a diagnostic limited TTE in 94% of patients and interpreted their studies correctly in 84%. Limited TTE provided new cardiac information and changed management in 37% of patients. TTE added useful information in an additional 47% of patients but did not alter immediate management. The mean "goal-directed TTE" acquisition time was 10.5 +/- 4.2 minutes.

CONCLUSION

After a brief formal training in using this handheld echocardiographic system in intensive care unit patients, surgical intensivists successfully performed and correctly interpreted a limited TTE in critically ill patients. Limited TTE provided new information and altered management in a significant number of patients. This study supports incorporating bedside goal-directed, limited TTE into intensivists' training programs.

Delayed pericardial tamponade after penetrating chest trauma

Delayed pericardial tamponade (PT) after penetrating heart trauma is now a rare condition as a result of advances in medical and surgical management. We report the case of a 32-year-old man with delayed PT after a stab wound from a knife. The initial evaluation was consistent with a traumatic apical myocardial infarction. After an uneventful initial course, the patient developed acute PT, which required emergency surgery. A thrombus was discovered over a laceration in the mid-segment of the left anterior descending artery and a simple suture was performed.

Severe refractory hypoxemia following a gunshot injury

We describe the case of a 57-year-old man with severe refractory hypoxemia, despite receiving ventilation therapy with 100% oxygen, following a gunshot wound to his left chest. A limited CT scan of the chest with contrast raised the suspicion of an arteriovenous (AV) fistula. Contrast-enhanced transthoracic echocardiography confirmed the presence of a pulmonary AV fistula. Traumatic pulmonary AV fistula is a rare, but serious and life-threatening condition that should be suspected in patients with thoracic injuries with persistent unexplained hypoxemia. Contrast echocardiography is a relatively simple, inexpensive, and readily available bedside test that can be used to confirm this diagnosis.

Bedside limited echocardiography by the emergency physician is accurate during evaluation of the critically ill patient

OBJECTIVE

Echocardiography can be a rapid, noninvasive, objective tool in the assessment of ventricular function and preload during resuscitation of a critically ill or injured child. We sought to determine the accuracy of bedside limited echocardiography by the emergency physician (BLEEP) in estimation of (1) left ventricular function (LVF) and (2) inferior vena cava (IVC) volume, as an indirect measure of preload.

METHODS

We conducted a prospective observational study of a convenience sample of patients who were admitted to our intensive care unit. All patients underwent BLEEP followed by an independent formal echocardiogram by an experienced pediatric echocardiography provider (PEP). IVC volume was assessed by measurement of the maximal diameter of the IVC. LVF was determined by calculating shortening fraction (SF) using M-mode measurements on the parasternal short-axis view at the level of the papillary muscle. An independent blinded pediatric cardiologist reviewed all images for accuracy and quality. Estimates of SF obtained on the BLEEP examination were compared with those obtained by the PEP.

RESULTS

Thirty-one patients were enrolled. The mean age was 5.1 years (range: 23 days-16 years); 48.4% (15 of 31) were girls; 58.1% (18 of 31) were on mechanical ventilatory support at the time of their study. There was good agreement between the emergency physician (EP) and the PEP for estimation of SF (r = 0.78). The mean difference in the estimate of SF between the providers was 4.4% (95% confidence interval: 1.6%-7.2%). This difference in estimate of SF was statistically significant. Similarly, there was good agreement between the EP and the PEP for estimation of IVC volume (r = 0.8). The mean difference in the estimate of IVC diameter by the PEP and the EP was 0.068 mm (95% confidence interval: -0.16 to 0.025 mm). This difference was not statistically significant.

CONCLUSIONS

Our study suggests that PEP sonographers are capable of obtaining images that permit accurate assessment of LVF and IVC volume. BLEEP can be performed with focused training and oversight by a pediatric cardiologist.

Feasibility of remote echocardiography with satellite transmission and real-time interpretation to support medical activities in the austere medical environment

Echocardiography is an essential tool in the evaluation of patients with cardiac emergencies and chest trauma. The objective of our study was to establish the feasibility and diagnostic accuracy of a portable satellite transmission system in the assessment of cardiac emergencies for the real-time support of mass casualty and humanitarian relief efforts. Twelve patients with various degrees of cardiac structural disease identified by conventional inhospital transthoracic echocardiography were transported to a remote portable field hospital where transthoracic echocardiography was performed with a handheld echocardiographic device. Images were then relayed by a commercial satellite to a level III trauma center where they were interpreted in real time by a cardiologist. Remote studies were recorded at the field hospital before satellite transmission and again on download at the receiving facility. The remotely acquired studies before and after satellite transmission were compared with each other and subsequently compared with conventional hospital transthoracic echocardiograms for technical quality and diagnostic accuracy using a blinded, single-reader, side-by-side comparison. Excellent agreement was found between the recorded field-site and satellite-transmitted images with an overall average of 95% concordance. When the field data acquired with the handheld device and satellite transmission were compared with conventional inhospital echocardiography, a high degree of agreement was demonstrated in overall technical quality (83%) and assessments of left ventricular ejection fraction (100%), pericardial effusion (100%), and left ventricular size (92%). This study demonstrates the feasibility and diagnostic accuracy of remote, real-time echocardiography using satellite transmission for mass casualty triage or humanitarian relief efforts.

Hand-Carried Ultrasound Improves the Bedside Cardiovascular Examination

OBJECTIVES

We assessed the clinical utility of hand-carried cardiac ultrasound (HCU) devices to assist physicians in the diagnosis of cardiovascular disease.

MATERIALS AND METHODS

We reviewed 42 articles published from 1978 to 2004.

RESULTS

The capability and simplicity of the HCU device assist physicians in the diagnosis of cardiovascular disease at the initial patients contact. HCU is particularly useful in the setting of emergency or critical care, community screening, or in remote areas with limited access to health care.

CONCLUSION

The inherent limitations of the physical examination as well as the reduced focus and training in physical diagnosis of current and recent medical school graduates has set the stage for the HCU device to modify traditional medical practices by complementing the physical examination with real-time cardiovascular imaging.

Cardiac ultrasound

The use of echocardiography in the ED is well established and continues to gain widespread use in the evaluation of critically ill patients. In certain circumstances such as chest trauma, pericardial effusion, and cardiac arrest,EPs can perform and interpret echocardiographic examinations reliably. In other circumstances such as the diagnosis of acute coronary syndromes, PE,and endocarditis, the EP should be aware of the uses and limitations of echocardiography and obtain appropriate consultation when necessary.Academic- and community-based EPs should seek to incorporate further the use of echocardiography in their respective clinical practices, with special attention given to training and quality assurance. As EPs continue to improve their skills in cardiac ultrasound, their ability to diagnose a wider spectrum of cardiac diseases undoubtedly will grow proportionally.

Ultrasound in abdominal trauma

This article reviews current issues regarding the Focused Assessment with Sonography for Trauma (FAST) examination. Technical performance issues, decision-making and practice algorithms, fluid volume and scoring systems, proficiency and training, and the role of the FAST in pediatric trauma are covered. This article examines the FAST examination from a practical, evidenced-based stand-point.

Bedside echocardiography in chest trauma

Bedside US has an established role in the evaluation of chest trauma patients. Transthoracic echocardiography and TEE can be used to obtain critical information at the bedside for many emergent conditions, including the immediate detection of hemopericardium and acute aortic injury. More recent work has demonstrated that US also can be used to detect hemothoraces and pneumothoraces with accuracy. These diagnostic techniques can improve patient outcome and are within the scope of practice of emergency physicians and trauma surgeons. Physicians caring for trauma patients should be familiar with these techniques.

Procedural applications of ultrasound

Many invasive procedures are now safer and more efficient with the use of ultrasound guidance. As emergency physicians continue to develop skills in sonography, new applications of this technology will continue to impact the practice of emergency medicine.

FAST (focused assessment with sonography in trauma) accurate for cardiac and intraperitoneal injury in penetrating anterior chest trauma

OBJECTIVE

To evaluate the FAST (focused assessment with sonography in trauma) examination for determining traumatic pericardial effusion and intraperitoneal fluid indicative of injury in patients with penetrating anterior chest trauma.

METHODS

An observational prospective study was conducted over a 30-month period at an urban level I trauma center. FAST was performed in the emergency department by emergency physicians and trauma surgeons. FAST results were recorded before review of patient outcome as determined by 1 or more of the following: thoracotomy, laparotomy, pericardial window, cardiologic echocardiography, diagnostic peritoneal lavage, computed tomography, and serial examinations.

RESULTS

FAST was undertaken in 32 patients with penetrating anterior chest trauma: 20 (65%) had stab wounds, and 12 (35%) had gunshot wounds. Sensitivity of FAST for cardiac injury (n = 8) in patients with pericardial effusion was 100% (95% confidence interval, 63.1%-100%); specificity was 100% (95% confidence interval, 85.8%-100%). The presence of pericardial effusion determined by FAST correlated with the need for thoracotomy in 7 (87.5%) of 8 patients (95% confidence interval, 47.3%-99.7%). One patient with a pericardial blood clot on cardiologic echocardiography was treated nonsurgically. FAST had 100% sensitivity for intraperitoneal injury (95% confidence interval, 63.1%-100%) in 8 patients with views indicating intraperitoneal fluid but without pericardial effusion, again with no false-positive results, giving a specificity of 100% (95% confidence interval, 85.8%-100%). This prompted necessary laparotomy in all 8.

CONCLUSIONS

In this series of patients with penetrating anterior chest trauma, the FAST examination was sensitive and specific in the determination of both traumatic pericardial effusion and intraperitoneal fluid indicative of injury, thus effectively guiding emergent surgical decision making.

Performance, training, quality assurance, and reimbursement of emergency physician-performed ultrasonography at academic medical centers

OBJECTIVE

To determine the current state of bedside emergency physician-performed ultrasonography in terms of prevalence, training, quality assurance, and reimbursement at emergency medicine residency programs.

METHODS

The link to a 10-question Web-based survey was e-mailed to ultrasound/residency directors at 122 emergency medicine residency programs in the United States.

RESULTS

The overall response rate was 84%. Ninety-two percent of programs reported 24-hour emergency physician-performed ultrasonography availability. Fifty-one percent of programs reported that a credentialing/privileging plan was in place at their hospital, and 71% of programs had a quality assurance/image review procedure in place. Emergency medicine specialty-specific guidelines of 150 ultrasonographic examinations and 40 hours of didactic instruction were met by 39% and 22% of residencies, respectively, although only 13.7% of programs were completing the 300 examinations recommended by the American Institute of Ultrasound in Medicine. Sixteen programs (16%) reported that they were currently billing for emergency physician-performed ultrasonography; of those not billing, 10 (12%) planned to bill within 1 year, and 32 (37%) planned to bill at some point in the future.

CONCLUSIONS

Performance and training in emergency physician-performed ultrasonography at academic medical centers continues to increase. The number of emergency medicine residency programs meeting specialty-specific guidelines has more than doubled in the last 4 years, but only a small number are meeting American Institute of Ultrasound in Medicine guidelines. Although only 16% of programs reported that they were currently billing for emergency physician-performed ultrasonography, most had plans to bill in the future.

Emergency echocardiography to detect pericardial effusion in patients in PEA and near-PEA states

OBJECTIVES

Emergency echocardiography (EM echo) has been proposed to assist in decision-making in patients with pulseless electric activity (PEA) or PEA-like states. We observed the value of EM echo by emergency physicians in detecting pericardial effusion in patients in PEA and near PEA states.

MATERIALS AND METHODS

Observational, prospective series at a Level 1 urban ED of patients with non-traumatic PEA or near PEA states who had EM echoes performed by emergency physicians during an 18-month period. Outcomes of patients with EM echoes were established by review of clinical course, formal echocardiography, radiography, operation or autopsy.

RESULTS

Twenty patients had EM echo for non-traumatic hemodynamic collapse. Eight of 20 patients (40%) were without cardiac ventricular motion and were refractory to ACLS measures. Twelve of 20 (60%) patients had cardiac kinetic motion observed on echo. Eight of the 12 (67%) patients with cardiac motion had a pericardial effusion observed on EM echo. Formal echocardiography or other imaging studies confirmed all pericardial effusion cases. The following diagnoses were subsequently confirmed in patients with pericardial effusion: one aortic aneurysm, two aortic dissections, two metastatic cancers, one post-dialysis effusion, two minimal effusions. Three patients had tamponade with emergency pericardial drainage or surgery. In two of four patients with cardiac activity without pericardial effusion, EM echo was useful by detecting pacer capture and ROSC, respectively.

CONCLUSIONS

Emergency echocardiography performed by emergency physicians in patients in PEA or near PEA states can detect pericardial effusions with correctable etiologies versus true PEA with ventricular standstill.

Successful diagnosis of penetrating cardiac injury using surgeon-performed sonography

BACKGROUND

Patients with penetrating cardiac injuries have a high mortality. The utilization of sonography in these patients may lead to earlier diagnosis and definitive surgical intervention.

METHODS

A retrospective review of all patients admitted to a level I trauma center were examined from March 1996 to March 2001 (17,241 patients). Patients were identified with penetrating thoracic injuries and were evaluated for mechanism of injury, sonographic findings (subxiphoid and parasternal windows), injury severity score, length of stay, and mortality. Surgeons performed all sonography.

RESULTS

There were 478 patients who underwent sonography for penetrating thoracic injuries. Twenty-three patients were identified with positive sonographic findings. Subsequently 20 patients had a cardiac injury at surgery. There were no missed injuries. The 3 patients with false positive findings had congestive heart failure (2 patients) and morbid obesity (1 patient). Mean time to operation was 13 minutes. Mean injury severity score was 33. Mean intensive care unit and hospital stay was 3.1 days and 7.2 days respectively. Sonography had a specificity of 99.3% and sensitivity of 100% for identifying penetrating cardiac injury and a positive predictive value of 87% and negative predictive value of 100%. There were no hospital deaths.

CONCLUSIONS

Early diagnosis and management using surgeon performed sonography may reduce the high mortality associated with penetrating cardiac injury.

Feasibility of real-time echocardiographic evaluation during patient transport

Echocardiography is a key diagnostic tool in evaluating patients with cardiac emergencies and chest trauma. The lack of qualified real-time interpretation limits its use by emergency first responders. Early diagnosis of cardiac emergencies has the potential to facilitate triage and medical intervention to improve outcomes. We investigated the feasibility of remote, real-time interpretation of echocardiograms during patient transport. Echocardiograms using a hand-carried ultrasound device were transmitted from an ambulance in transit to a tertiary care facility using a distributed mobile local area network. Transmitted studies were reviewed by a cardiologist for ability to interpret predefined features. Transmission quality and reliability were assessed. Echocardiographic images were successfully transmitted greater than 88% of transport time. The evaluation of left-ventricular size and function, and presence of pericardial effusion were greater than 90% concordant, but only 66% of all echocardiographic features were concordant. Most transmission losses were brief (<or=10 seconds) with little impact on interpretability. Wireless infrastructures in metropolitan areas provide the ability for real-time transmission of echocardiograms during patient transport of adequate quality for accurate interpretation.

Pediatric pericardial tamponade presenting as altered mental status

The purpose of this case report is to illustrate the diagnostic difficulties of pericardial tamponade and to suggest that focused cardiac ultrasound be included in the resuscitative care of pediatric shock. Three cases of cardiac tamponade are presented. Each patient had a syncopal episode and presented with altered mental status and hypotension. Muffled heart tones, distended neck veins, and electrocardiogram and chest radiograph abnormalities were not present. Hypotension was not responsive to intravenous volume expansion treatment. Diagnostic delays would have been prevented if focused cardiac ultrasound had been included in the resuscitative care of shock.

Limited cardiac ultrasound examination for cost-effective echocardiographic referral

BACKGROUND

Although a standard echocardiogram is frequently requested and requires significant resources, few data exist on methods to improve referral for this examination. Therefore, we sought to determine the diagnostic value of a limited echocardiographic examination and to predict the cost-effectiveness of a limited imaging strategy on echocardiographic referral.

METHODS

A limited echocardiographic examination was reviewed for abnormalities and compared with standard echocardiographic findings. Assuming an imaging strategy in which a normal limited echocardiographic examination would negate the need for standard echocardiography, we calculated the diagnostic yields, the number of full echocardiographic studies eliminated, and the number of abnormal cases missed. We also stratified data by patient age (< or > or = 65 years), inpatient versus outpatient status, gender, referral diagnosis, and referring physician subspecialty.

RESULTS

In 151 outpatients, overall diagnostic yield was 47% (95% CI [39%, 55%]), and was lower in those younger than 65 years, in women, and in noncardiologist referral. In 155 inpatients, yields were 75% (95% CI [67%, 83%]) and were also related to age, but not to gender, diagnosis, and physician subspecialty. Sensitivity, specificity, negative and positive predictive values, and accuracy for the limited echocardiographic examination was 77%, 72%, 67%, 81%, and 75%, respectively. The limited imaging strategy negated 70% of studies in the outpatient group younger than 65 years, with a less than 5% chance of missing a clinically significant finding.

CONCLUSION

A limited echocardiographic imaging strategy is most cost-effective when used in young outpatients, where it can result in a substantial reduction in referral for standard echocardiography while rarely missing findings.

Cardiac Trauma (Penetrating and Blunt) and Anesthetic Issues

Patients with blunt or penetrating trauma can require anesthesia and surgery for cardiac injury in the face of noncardiac trauma, or can require anesthesia and surgery for noncardiac injury in the face of cardiac trauma. The true incidence of blunt cardiac trauma is not known, and estimates vary widely with different diagnostic criteria. The diagnosis of traumatic cardiac injury, particularly bluntcardiac injury, may be difficult even with a wealth of available diagnostic tools. Both blunt and penetrating trauma can result is a variety of injuries to cardiac structures. Manifestations of acute traumatic cardiac injury can differ from the clinical manifestations ofsimilar defects in the chronic setting on physical examination, radiography, and in symptomatology. There may be sequelae of traumatic injury which persist, or which may not become apparent for some period of time. Inexpensive, easily-interpreted laboratory criteria for reliably diagnosing cardiac trauma remain. Preexisting cardiacdisease and acute myocardial injury can complicate appropriate resuscitation from massive noncardiac injury. In general, and if unassociated with major noncardiac injuries, patients with cardiac injury be managed with low perioperative mortality.

Significant hemoperitoneum in blunt trauma victims with normal vital signs and clinical examination

Clinical examination of the abdomen is generally reliable in stable trauma patients with no distracting or head injury. Patients involved in relatively minor trauma with normal examinations can be safely sent home in most instances. We report 6 cases of blunt abdominal trauma that had completely normal clinical examinations and vital signs but were found to have significant hemoperitoneum on trauma ultrasound examination. Four of the patients were examined for educational purposes just before planned discharge from the emergency department. These cases suggest that a screening ultrasound examination may have a role in the evaluation of most blunt trauma patients.

The effect of real time 2-D-echocardiography on medical decision-making in the emergency department

2-D Echocardiography (ECHO) represents an important tool for the evaluation of the Emergency Department (ED) patient with suspected cardiovascular (CV) pathology. The present study assesses the degree of effect of real time ECHO on Emergency Physician diagnosis, treatment, and disposition of CV patients and their level of confidence in these decisions. One hundred ED patients with suspected CV pathology were enrolled into this prospective, interventional study. Senior level physicians were asked their level of confidence regarding patient diagnosis, treatment, and disposition decisions before and after the ECHO was done and interpreted by a certified sonographer in the ED. Physicians were then asked if ECHO changed any of these decisions. Patient age was 56.4 +/- 15.8 (range 27-93) years. Chest pain (n = 45) and shortness of breath (n = 38) were the most common presenting symptoms. Eighty-six of the patients were admitted. There was a change in diagnosis in 37 patients, a change in treatment in 25 patients, and a change in disposition in 11 patients. Physicians indicated there was a change in confidence level post-ECHO in approximately 50% of patients. A significant change was seen in both a more and a less confident direction. Physicians were 3 times more confident regarding diagnosis, 7 times more confident regarding treatment, and 3 times more confident regarding disposition decision-making. Real time ECHO appears to have a significant level of impact on physician level of confidence and medical decision-making concerning patients with suspected cardiovascular pathology in the ED.